Question

A flagpole casts a shadow 16 feet long.

Shanika is standing near the pole. Her
shadow is 4 feet long. Shanika's height is 5
feet. How tall is the flagpole?

Answer 1

Explanation:

Since Shanika is standing near the pole, we can safely assume that the triangle formed by Shanika and her shadow is a smaller version of the triangle formed by the pole and its shadow.

By similar triangles:

`(x \: of \: pole)/(y \: of \: pole) = (x \: of \: shanika)/(y \: of \: shanika) \\ (16)/( height \: of \: pole) = (4)/(5) \\ 16(5) = 4 * height \: of \: pole \\ height \: of \: pole = (80)/(4) \\ = 20`

The height of the pole is 20ft.